Tài liệu Structures congress 2017 bridges and transportation structures

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Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Structures Congress 2017 Bridges and Transportation Structures Selected Papers from the Structures Congress 2017 Denver, Colorado April 6–8, 2017 Edited by J. G. (Greg) Soules, P.E., S.E., P.Eng Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Structures Congress 2017 Bridges and Transportation Structures SELECTED PAPERS FROM THE STRUCTURES CONGRESS 2017 April 6–8, 2017 Denver, Colorado SPONSORED BY The Structural Engineering Institute (SEI) of the American Society of Civil Engineers EDITED BY J. G. (Greg) Soules, P.E., S.E., P.Eng Published by the American Society of Civil Engineers Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Published by American Society of Civil Engineers 1801 Alexander Bell Drive Reston, Virginia, 20191-4382 www.asce.org/publications | ascelibrary.org Any statements expressed in these materials are those of the individual authors and do not necessarily represent the views of ASCE, which takes no responsibility for any statement made herein. No reference made in this publication to any specific method, product, process, or service constitutes or implies an endorsement, recommendation, or warranty thereof by ASCE. The materials are for general information only and do not represent a standard of ASCE, nor are they intended as a reference in purchase specifications, contracts, regulations, statutes, or any other legal document. ASCE makes no representation or warranty of any kind, whether express or implied, concerning the accuracy, completeness, suitability, or utility of any information, apparatus, product, or process discussed in this publication, and assumes no liability therefor. The information contained in these materials should not be used without first securing competent advice with respect to its suitability for any general or specific application. Anyone utilizing such information assumes all liability arising from such use, including but not limited to infringement of any patent or patents. ASCE and American Society of Civil Engineers—Registered in U.S. Patent and Trademark Office. Photocopies and permissions. Permission to photocopy or reproduce material from ASCE publications can be requested by sending an e-mail to permissions@asce.org or by locating a title in ASCE's Civil Engineering Database (http://cedb.asce.org) or ASCE Library (http://ascelibrary.org) and using the “Permissions” link. Errata: Errata, if any, can be found at https://doi.org/10.1061/9780784480403 Copyright © 2017 by the American Society of Civil Engineers. All Rights Reserved. ISBN 978-0-7844-8040-3 (PDF) Manufactured in the United States of America. Structures Congress 2017 iii Prreface Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. The Structures Congress C hass a robust tecchnical proggram focusinng on topics important too Strucctural Engin neers. The papers in the proceeding g are organizzed in 4 voluumes ume 1 includ des papers on n Blast and Impact I Loadding and Ressponse of Strructures Volu Volu ume 2 includ des papers on n Bridges an nd Transporttation Structuures Volu ume 3 includ des papers on n Buildings and Nonbuillding and Sppecial Structtures Volu ume 4 includ des papers on o Other Strructural Enggineering Toppics includinng; Business and Professional Practice, Natural N Disaasters, Nonsttructural Syystems and C Componentss, orensics Educcation, Research, and Fo Acknow A wledgm ments Prep paration for the Structurres Congress required ssignificant tiime and efffort from thee mem mbers of th he National Technicall Program Committeee, the Loccal Planningg Com mmittee. Mucch of the succcess of the conference c rreflects the ddedication annd hard workk by th hese volunteeers. We would w like to thank GEIICO and Peaarl for Sponssoring the Congress procceedings andd supp porting the Structures Co ongress in su uch a generouus way. The Joint Progrram Committtee would like l to acknnowledge thee critical suupport of thee spon nsors, exhibiitors, presen nters, and mo oderators whho contributted to the suuccess of thee confference throu ugh their parrticipation. o dedicated volunteerrs and staff, f, we wouldd like to thank you for On behalf of our nding your valuable v timee attending the t Structurees Congresss. It is our hhope that youu spen and your y colleag gues will ben nefit greatly from the infformation prrovided, learrn things youu can implement i and a make pro ofessional co onnections thhat last for yyears. Sinccerely, J. Grreg Soules, P.E., P S.E., P..Eng, SECB, F.SEI, F.A ASCE © ASCE Structures Congress 2017 iv Contents Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Bridges and Transportation Structures Evaluation of Bond Strength for AFRP Reinforcing Bars in Columns with Self-Consolidating Concrete ...................................................................................... 1 Emmanuel Chinaka, Mehdi Shokouhian, Steve Efe, and Monique Head Dolores River Bridge—Bedrock, CO: Remote Site Solution for Deep Scour ..... 12 Jonathan E. Emenheiser and Gregory S. Lingor Performance Evaluation of High-Performance Isolation Rubber Bearings for the Seismic Mitigation of Bridge Structures .................................................... 24 Han Li, Shengze Tian, Wancheng Yuan, and Kai Wei Fragility Analysis of a Continuous Gird Bridge Subjected to a Mainshock-Aftershock Sequence Considering Deterioration .............................. 36 Zhengnan Wang, Yutao Pang, and Wancheng Yuan Seismic Response of the Integral Abutment Bridges............................................. 48 D. L. Kozak, J. Luo, J. M. LaFave, and L. A. Fahnestock Parametric Study of the External Strengthening of Composite Beams Using Post-Tensioned Tendons .......................................................................................... 58 Ayman El-Zohairy and Hani Salim Investigating and Resolving Bridge Grouted PT-Strand Corrosion Problems .................................................................................................................... 68 David Whitmore, Tore Arnesen, and Brian Pailes Reliability Analysis of Existing Bridge Deep Foundations for Reuse .................. 76 Nathan Davis, Ehssan Hoomaan, Masoud Sanayei, and Anil Agrawal Examination of Steel Pin and Hanger Options—Retrofit to Replacement ......... 87 Chandana C. Balakrishna and Daniel G. Linzell Structural Challenges in the Design of Three Pedestrian Bridges ....................... 98 Hohsing Lee Reconstructing History: Redesigning Historic Bridges to Meet Today’s Greater Demands .................................................................................................... 108 Christian Wiederholz and Leo Fernandez © ASCE Structures Congress 2017 Feeding System of the Segments in the Main Span for the New Champlain Cable-Stayed Bridge ........................................................................... 118 Gonzalo Osborne, Taner Aydogmus, and Jeff Rogerson Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Experimental and Analytical Investigation of the Reynolds Number Effect on Wind Forces for Multi-Girder Bridges ........................................................... 136 Ramtin Kargarmoakhar and Maryam Asghari Mooneghi Retrofitting Distortion-Induced Fatigue in Skewed Girders to Cross-Frame Connections ...................................................................................... 149 Danqing Yu, Caroline Bennett, and Adolfo Matamoros Redundancy and Fracture Resilience of Built-Up Steel Girders ....................... 162 Matthew H. Hebdon, Japsimran Singh, and Robert J. Connor Impact Factor Determination for High-Speed Rail Bridges............................... 175 Andrew R. Kimmle and Carlos G. Matos Fanny Appleton Pedestrian Bridge: From Base Technical Concept to Final Design ............................................................................................................. 188 W. R. Goulet and M. C. Barth Investigation into a Simplified Dynamic Analysis for Simple Span High-Speed Rail Structures ................................................................................... 200 Scott H. Henning and Ken Lee A Methodology for the Dynamic Analysis of Railway Bridges Subjected to Vehicular Loads ...................................................................................................... 213 J. E. Abdalla Filho, F. L. M. Beghetto, and J. P. R. Remor A Computational Framework for the Aerodynamic Shape Optimization of Long-Span Bridge Decks ........................................................................................ 223 T. H. Birhane, G. T. Bitsuamlak, and J. P. King Proposed Framework for the Performance-Based Seismic Design of Highway Bridges ..................................................................................................... 240 H. Ataei, M. Mamaghani, and E. M. Lui Enhancing the Modeling of UHPC Connections Subjected to Fatigue Loading for Modular Concrete Bridge Deck Design........................................... 254 Mi G. Chorzepa and Amin Yaghoobi Infrastructure Recovery for Resilience Quantification....................................... 264 Bernardo Crespo Sánchez-Peral © ASCE v Structures Congress 2017 Pattern Recognition in the National Bridge Inventory for Automated Screening and the Assessment of Infrastructure ................................................. 279 Mohamad Alipour, Devin K. Harris, and Laura E. Barnes Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Influence of Horizontal Curvature on the Shear Resistance of Steel Plate Girders with Slender Webs .................................................................................... 292 Bernard A. Frankl and Daniel G. Linzell A Railroad Perspective on Bridge Measurement and Monitoring Systems ...... 302 Duane Otter, John F. Unsworth, and James N. Carter Jr. Repairing Distortion-Induced Fatigue Cracking in a Seismically Retrofitted Steel Bridge: Field Test ...................................................................... 314 Mehdi Motaleb, Nick Duong, Will Lindquist, and Riyadh Hindi Comparison of Models for the Design of Portal Frame Bridges with Regard to Restraint Forces .................................................................................... 326 E. Gottsäter, O. Ivanov, R. Crocetti, M. Molnár, and M. Plos Behavior of FRP Retrofitted Bridge Timber Piles under Earthquake and Tsunami Loading .................................................................................................... 340 Kun-Ho Eugene Kim, Bassem Andrawes, and C. A. Duarte A Tunnel Grows in Brooklyn: How an Innovative Portal Structure Minimized Impacts on Bustling Atlantic Avenue and Long Island Rail Road Operations in NYC ............................................................................... 353 Stuart Lerner and Pak Ki So Rapid Seismic Repair of Severely Damaged Reinforced Concrete Bridge Piers ............................................................................................................. 370 Ruo-Yang Wu and Chris P. Pantelides Experimental Evaluation and Development of a Self-Centering Friction Damping Brace........................................................................................................ 382 Syed Adnan Khader, David Naish, and Joel Lanning Behavior of Retrofitted UHPC Beams Using Carbon Fiber Composites under Impact Loads ............................................................................................... 392 S. Nasrin, A. Ibrahim, M. Al-Osta, and U. Khan Strength, Ductility, and Prestress Losses of Unbonded Post-Tensioning Strands in Self-Centering Structures .................................................................... 403 Cancan Yang, Maria Lopez Ruiz, and Pinar Okumus © ASCE vi Structures Congress 2017 Comparison of the Seismic Retrofit of a Three-Column Bridge Bent with Buckling Restrained Braces and Self Centering Braces ..................................... 414 A. Upadhyay and C. P. Pantelides Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Dynamic Time History Response of Irregular Bridges ....................................... 424 Majid Tamanani and Ashraf Ayoub Impact of the Overloading of Heavy Goods Vehicles on the Fatigue Life of Steel Bridges ............................................................................................................ 434 A. Q. Ayilara and M. S. Liew Effect of Seismic Retrofitting on the Behavior of RC Bridge Columns Subjected to Main Shock-Aftershock Sequences ................................................. 446 Mehdi Rostamian, Farid Hosseinpour, and Adel E. Abdelnaby Automated Structural Modelling of Bridges from Laser Scanning ................... 457 Yujie Yan, Burcu Guldur, and Jerome F. Hajjar The Effect of Superstructure Curvature on the Seismic Performance of Box-Girder Bridges with In-Span Hinges ............................................................ 469 F. Soleimani, C. S. W. Yang, and R. DesRoches Effects of Ground Motion Incidence Angles in a Reinforced Concrete Skewed Bridge Retrofitted with Bucking Restrained Braces ............................. 481 Yuandong Wang, Luis Ibarra, and Chris Pantelides Mechanical Evaluation of Corrosion-Resistant Steel Plates for Bridge Girder Fabrication.................................................................................................. 494 Sherif M. Daghash and Osman E. Ozbulut Unbonded Tendons as an Alternative for Bonded Tendons in Post-Tensioned Bridges: Constructability, Structural Performance, and Monitoring ............................................................................................................... 506 A. B. M. Abdullah, Jennifer A. Rice, Rahul Bhatia, Natassia R. Brenkus, and H. R. Hamilton Collapse Fragility Analysis of Non-Seismically Designed Bridge Columns Retrofitted with FRP Composites ......................................................................... 517 Anant Parghi and M. S. Alam Truckee River Bridge—Tahoe City, CA: Trail Access below a River Bridge ............................................................................................................ 533 John G. Rohner and Jonathan E. Emenheiser © ASCE vii Structures Congress 2017 1 Evaluation of Bond Strength for AFRP Reinforcing Bars in Columns with SelfConsolidating Concrete Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Emmanuel Chinaka1; Mehdi Shokouhian2; Steve Efe3; and Monique Head4 1 CBEIS 232, Dept. of Civil Engineering, Morgan State Univ., Baltimore, MD 21251. E-mail: emchi1@morgan.edu 2 CBEIS 205, Dept. of Civil Engineering, Morgan State Univ., Baltimore, MD 21251. E-mail: mehdi.shokouhian@morgan.edu 3 CBEIS 233, Dept. of Civil Engineering, Morgan State Univ., Baltimore, MD 21251. E-mail: steve.efe@morgan.edu 4 CBEIS 209, Dept. of Civil Engineering, Morgan State Univ., Baltimore, MD 21251. E-mail: monique.head@morgan.edu 1700 E. Cold Spring Ln., 1700 E. Cold Spring Ln., 1700 E. Cold Spring Ln., 1700 E. Cold Spring Ln., Abstract Previous research and design codes have focused on developing equations, mostly empirical based on experimental studies, to determine the bond strength of steel bars with different types of concrete. However, limited studies have been conducted on FRP bars particularly embedded in Self-Consolidating Concrete (SCC), but very few using Aramid Fiber Reinforced Polymers (AFRP) bars. This investigation aims to study the influence of two main parameters: 1) superplasticizer dosage and 2) water to cement ratio on the bond strength and bond slip model of the AFRP bars and SCC. Results show a significant effect of superplasticizer on the bond strength of AFRP bars embedded within SCC. Moreover, the effect of the w/c ratio is quantified and its correlation with bond strength is presented. The slippage of the AFRP bars embedded in the concrete was accurately measured to determine a precise bond-slip model that is compared to conventional concrete performance. 1. Introduction SCC is a type of concrete that was developed and introduced in Japan in the late 1980s by Professor Hajime Okamura (Zia, et al., 2005). SCC has the ability to flow using its self-weight without the need for vibration. This idea and concept were motivated by the lack of workers needed for construction. In the 1990s, the United States began implementing SCC for infrastructure. In North America and other places in the world, SCC has been used for substructure repair such as bridge repair. The annual cost of concrete repairs in North America is about $20 billion, and a significant amount of the money is spent on bridge substructure repairs (Orangun, et al., 1977). The use of SCC is becoming more widespread due to its high flow ability and durability. The use of SCC allows for a reduction in labor and mechanical vibration, and better construction environment due to the elimination of the noise. Studies have been conducted to understand the movement and flow of SCC, while also understanding the components that will affect it. The reduction of labor costs, better self-leveling, and elimination of consolidation noise on job sites is a major reason why the use of SCC is widely growing in precast construction (Ghafoori, et al., (2014)- (Kassimi, et al., 2014). A great amount of research and understanding must go into SCC, considering the benefits that are associated with it in order to attain full potential of this material (Gibb, et al., 2012). The main additive in SCC, which makes it self-consolidating is superplasticizer (SP). This additive allows a reduction in the water to cement ratio of the concrete that in return will increase the compressive strength, and allow for © ASCE Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Structures Congress 2017 great workability of the concrete. Given the demand to use corrosion-resistant bars in the reinforced concrete members, coupled with the advantages of SCC, this research explores the bond strength of aramid fiber reinforced polymer (AFRP) bars when used in conjunction with SCC. In addition to further understanding the bond behavior of the bar and the concrete during loading, a bond slip model can display the movement and actual bonding of the bar and concrete. Perfect bonding is something that is assumed in most numerical studies of FRP reinforced concrete structures which results in non-realistic and imprecise predictions of the behavior of the structure (Lin & Zhang, 2013). Giving that the amount of data on the bond slip of FRP bars and SCC is limited, it is important that data is acquired in order to obtain an understanding and to ensure adequate bonding behavior. As previously stated, there is a lack of experimental data to express the bonding behavior between SCC and the AFRP bars for structural concrete design. Therefore, this study will provide more data concerning this concept through a series of pullout tests using AFRP bars in SCC to understand the effects of the superplasticizer and water cement ratio on the bond strength and bond slip model. 2. Previous research Separately research on bond behavior of FRP bars and SCC is a topic which is becoming more frequent, but information of AFRP bars embedded in SCC is very limited. Research was done to show the effects of superplasticizer on the steel-concrete bond strength, (Brettmann, et al., 1986). Several different variables were taken into account in this research. The degree of consolidation and the slump of the concrete were key variables within this research. In addition, the concrete temperature and the placement of the bars were investigated as well. Result showed that high slump concrete had a higher bond strength than the concrete with low slump. Results showed that vibration on the concrete had a positive effect on the bond strength of the FRP bars and the concrete. Testing was conducted where steel and GFRP bars were studied to show how bleeding, statistical and dynamical segregation had an effect on the bond between the bars and SCC. The bond behavior of SCC was compared to that of normal concrete (Golafshani, et al., 2014). The results given by this test showed that the bond behavior for suitable adhesion treatment of steel bars is higher than that of GFRP bars. As well, reducing the water to cement ratio and substituting it with a high powder material decreases the bond strength variations. Data shows that AFRP bars have a higher tensile strength, elastic modulus and ultimate strain compared to that of other FRP bars. From the AFRP bars that were tested, results showed that it had a bond strength ranging from 1724–2537 MPa, elastic modulus ranging from 41–125 GPa and an ultimate strain ranging from 1.9-4.4%. These values obtain are shown to be much greater than that of Glass fiber reinforcing polymers (GFRP) bars (Kocaoz, et al., 2015). Research was performed that further looked into the bond behavior of AFRP and CFRP (Aramid and Carbon) bars and normal concrete, (Lee, et al., 2013). This research aims to investigate how the physical characteristic such as the bar diameter and the embedment length of the AFRP and CFRP bar effect the bond behavior. This research states that an increase in embedment length and bar diameter have negative effect on the bond strength of the bar and the concrete. Data on the bond slip of AFRP bars is something that is very limited and rare compared to that of steel bars. 30 pullout tests on GFRP bars and normal strength concrete were performed (Tastani, et al., 2005). The bar roughness and the diameter of the bar were parameter considered inside of this experiment. Results showed that the bond slip curve had a stiffer response with a lower bond stress with the smoother bar surfaces. © ASCE 2 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Structures Congress 2017 3 The bond behavior of high strength concrete (HSC) and steel bars at early ages of the concrete was investigated through a series of test, (Shen, et al., 2016). Knowing that reinforcement plays an effect on the cracking of concrete, it is important that the bond behavior and bond slip behavior are captured from this testing. The result showed that the bond strength of the steel increased with the age of the concrete. The bond strength of the steel and HSC increased as well as the compression strength. It was shown that the slip corresponding to the bond strength decreases with increasing compressive strength. Pullout tests were performed which looked into the bond behavior of deformed steel bars and plain steel bars (Xing, et al., 2015). The components tested in this research was the embedment length within the concrete and the physical surface features of the bars used. The result gathered from this test stated that plain smooth bars had a lower bond stress than that of deformed steel bars. The test results show that at an early stage there is no slip, however, the slip increases rapidly once it reaches the maximum bond stress. Table 1 Bond Equations (SI units) No Reference 1 ACI 440.1R-06 (Anon., 2006) 2 ACI 318-02 (Anon., 2002) 3 4 ACI 408 R-03 (Anon., 2003) Australian Standard (Anon., 1994) Equation √ Material Type Bar Concrete Normal-Weight FRP Concrete Steel (Unconfined) √ √ √ Steel Steel Normal-Weight Concrete Normal-Weight Concrete Normal-Weight Concrete Normal Strength Concrete 5 (Esfahani & Rangan, 1998) (Esfahani & Rangan, 1998) Steel 6 (Esfahani & Rangan, 1998) (Esfahani & Rangan, 1998) Steel High Strength Concrete 7 (Okelo & Yuan, 2005) FRP Normal-Weight Concrete = Concrete cover = bar diameter = compression strength of concrete = Bond Strength √ = embedded length of bar = development length of the steel rebar ( = 0.55√ ) = Bond Force = Minimum concrete cover = Axial tensile strength of concrete As stated previously, the amount of information concerning AFRP bars embedded in SCC is very limited. In order to address the gap in information for AFRP bars and SCC, experimental testing is performed to investigate the effect of the design mixture and the additives of SCC on the bonding strength of the concrete and AFRP bars. The bond slip relationship is investigated to examine the movement of the bar during loading. This is important for future knowledge and predicting the bond behavior of reinforcement and concrete. 3. Bond strength and bond slip equation From previous papers and codes, several equations were used to predict the bond strength of several types of FRP bars and steel bars in different types of concrete. A large amount of the © ASCE Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Structures Congress 2017 4 empirical equation used are formed from experimental studies. Table 1 display the several equations that were used to find the bond strength of several types of concrete and bars. The equations displayed in Table 1 contain the primary parameters, concrete cover, embedment length and the compression strength. The second phase of testing was centered on bond slip model for AFRP bars and self-consolidating concrete. The amount of information on FRP bars and SCC is very limited. The amount of equation that display the bond slip model is limited as well. In Table 2, it displays the bond slip equation that were obtain from previous research. Table 2 Bond Slip Equation (SI Units) No Reference 1 (Melo, et al., 2015) 2 (Cosenza, et al., 1997) (Melo, et al., 2015) = Bond Stress = Maximum Bond Stress (A) = Ascending Branch Material Type Bar Equation ( ( ) Plain bars (A) ) 4 = Slip = Slip at Maximum Bond Stress (D) = Descending Branch FRP twisted bars (A) Plain Bars (D) = Parameter based of curve fitting of previous data 4. Experimental test description Two set of test were conducted using the AFRP bar and SCC. The first set of test consist of thirty-pullout test that were used to investigate the effect of the superplasticizer dosage on the bond behavior. The first set of test were split between AFRP bars and steel bars. The AFRP bars were split into five different groups with five different dosage of superplasticizer. Each group consist of three specimens. All groups contained a constant water to cement ratio of 0.4. The first group contained no dosage of superplasticizer (normal concrete). This is a reference point for the other groups of concrete. From this point, Groups 2 to 5 includes 5, 6, 7, 8 ounces of superplasticizers per 100 lbs. of cement The dimension for the concrete cubes used in the pullout testing were 200 mm3. This dimension used were propose by the ACI code 440 for FRP reinforcement (Anon., 2004). The design mixture used for the concrete contained a fine aggregate to total aggregates ratio of 0.5. The total aggregates were 75% of the total weight of the concrete. The coarse aggregate used in this mixture was #57 grey white stone, and the fine aggregate was washed concrete sand. The water content was carefully measured by weighing a certain amount of coarse and fine aggregates. The aggregates were left in an oven for 24 hours, and then reweighed to determine the water content of the aggregates. This data will represent the water content for the remainder of the coarse and fine aggregates. Using this information from the water content, the concrete mixture must be re-adjusted in order to incorporate the water content of the fine and coarse aggregates. As stated previously, the superplasticizer dosage varies in each group of concrete to test the effect of the superplasticizer dosage on the bond strength of the AFRP bars and the SCC. The dosages of superplasticizer which is used in each group of concrete (5 to 8 ounces of superplasticizer per 100 lbs. of cement) was recommended by a manufacturer. The AFRP bars used in the first set of testing contained a diameter of 0.5 inches. The AFRP bars are aramid with 60% fiber volume fraction and an epoxy resin type, which have a natural dark greyish color. All bars were then cut to have an overall length of 24 inches. Four inches of each bar are embedded into the concrete. © ASCE Structures Congress 2017 5 a Table 3 Concrete superplasticizer Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Set No. b Set I Set II mixture Group No. w/c Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Group 8 Group 9 0.4 0.4 0.4 0.4 0.4 0.44 0.40 0.36 0.32 and SP Dosage (oz. per 100 lbs. of cement) 0 5 6 7 8 6 6 6 6 dosage of ( ) 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 Figure 1 Instrumentations and measurements, (a) dial gauges, (b) actual slippage The second set of test consists only of AFRP bars. The AFRP bars used in this set have the same properties as the bars used for the initial testing. For this test the bond slip model was observed. In order to accurately capture the model, dial gauges were implemented on the testing equipment. The test consists of 4 different groups similar to that of the previous test with the water to cement ratio varying from 0.32 to 0.44. After the concrete is placed in the wooden formwork, it is left to harden for a full 24 hours. After this, it is placed in a waterbed to cure for an additional 6 days. This makes a full week after the concrete is mixed and poured in which it will be put under a compression and pullout test. Once the concrete was cured, compression test and pullout test were conducted using the UTM (universal testing machine) in the lab. In order to perform the pullout test, an apparatus was designed to contain the cubed specimens. Two steel plates and four steel rods were crafted together using steel bolts and nuts to create the apparatus. The second set consists of investigating the bond-slip relationship between the AFRP bars and the SCC. Two dial gauges were used to test the slippage of the AFRP bars. The first dial gauge was fixed to the AFRP bar to obtain relative slip reading between the bar and apparatus. The second dial gauges were fixed to the UTM to indirectly verify the slip measurement of the AFRP bars in the concrete. Factors such as slippage of the bar in the top grip, movement of the dial gauge on the bar and bar shredding were taken into account when preparing for this test (Figure 1). The actual slippage was obtained by using measuring equipment in order to validate reading of dial gauges. After the test was conducted, the specimens were carefully split open to measure the length of the void left once the bar was pulled out. This data was used to calibrate the reading of the dial gauges and determine a modification factor to adjust the time-slip reading. 5. Results Compression test were performed on the different groups of concrete. With these tests, a relationship was created to understand how the dosage of superplasticizer effects on the compression strength of the SCC. The cylinder specimen tested had a size of 100 mm radius and © ASCE 6 a height of 200 mm. From Group 1 with no dosage of superplasticizer, there is a 56% increase in bond strength to Group 2, which contains 5 oz. per 100 lbs. per cement. From Group 2 to Group 3, there is an 8% increase in compression strength. From this point, there is a 6.3% increase in compression strength to Group 4. From Group 4 there is an increase of 4.8% in compression strength from this point to Group 5. There is an overall increase of 88% in compression strength from Group 1, which contains no dosage of superplasticizer, to Group 5, which contains 8 oz. per 100 lbs. of cement. Table 4 Results of compression test (cylinder 100mm diameter and 200mm height) and slump flow Group No. Specimen No. Group 1 Group 2 Group 3 Group 4 Group 5 SSC-G1(1-3) SSC-G2(1-3) SSC-G3(1-3) SSC-G4(1-3) SSC-G5(1-3) Dosage of SP (oz. per 100 Lbs. Of Cement) 0 5 6 7 8 Average Compression Strength (MPa) 20.10 31.42 33.96 36.13 37.87 Slump Flow Inches (mm) N/A 13 (330.2) 16 (406.2) 21.5 (546.1) 25.5 (647.7) This data can be observed in Table 4. The data was displayed in Figure 2.a, to show the increase of compression strength with the increase of superplasticizer dosage. The slump flow was taken for each group of concrete. The data shows there is an increase in slump flow with addition of superplasticizer. There is an increase of 96% in slump flow from a superplasticizer dosage of 0 oz. per 100 lbs. of cement which has a slump flow of 13 inches to a slump flow of 25.5 inches which has dosage of 8 oz. per 100 lbs. of cement. This is due to the increase of followability that occurs when superplasticizer dosage is increased. This can be seen in the Figure 2b Pullout tests were performed for each group of concrete to see how the dosage of superplasticizer effects the bond behavior between the AFRP bars and SCC. Using the steel apparatus constructed, the pullout test was conducted. With this data, the relationship between the bond strength and dosage of superplasticizer will be determined. This data can be seen in Table 5. From the result shown, there is a polynomial relationship between the bond strength and 40 27 a 35 b 24 30 25 Group 1 Group 2 Group 3 Group 4 Group 5 20 15 Slump flow (inch) Compression Strength (MPa) Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Structures Congress 2017 21 18 15 12 0 2 4 6 8 Dosage of superplasticizer (Oz. per 100 lbs of cement) 4 5 6 7 8 Dosage of superplasticizer (Oz. per 100 lbs of cement) Figure 2 Effect of superplasticizer on compression strength and slump flow, (a) compression strength of concrete as a function of superplasticizer dosage, (b) influence of superplasticizer on slump flow © ASCE 9 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Structures Congress 2017 7 superplasticizer dosage. The result from the compression strength showed that there is a positive linear relationship between the compression strength and the dosage of superplasticizer. The relationship between the compression strength and the bond strength can now be determined. From the data, there is slight increase of 16% in bond strength from Group 1 (no dosage of superplasticizer) to Group 2 (5 oz. of 100lb of cement). From Group 2 to Group 3 there is drastic decrease in bond strength. The data shows there is a 25 % decrease in bond strength. From Group 3 to Group 4 the curve continues to decline with a decrease of 22 % in bond strength. From this point, there is a slight increase in bond strength from Group 4 to Group 5 of 10%. Overall, there showed to be a 16% increase from Group 1 to Group 2 and then a 36% decline in bond strength from Group 2 to Group 5. This data can be seen in Figure 3a. Table 5 Average results of the pullout test in the Set I Group No. Test No. G1 G2 G3 G4 G5 G1-S G2-S G5-S 1-3 4-6 7-9 10-12 13-15 16-18 19-21 22-24 Dosage of SP (ounces. per 100 lbs. Of Cement) 0 5 6 7 8 0 5 8 Bar type AFRP AFRP AFRP AFRP AFRP Steel Steel Steel Diameter Inches (mm) 0.5 (12.7) 0.5 (12.7) 0.5 (12.7) 0.5 (12.7) 0.5 (12.7) 0.56 (14.3) 0.56 (14.3) 0.56 (14.3) Peak Load (lbf) 6454 7527 5610 4336 4796 12085 12030 12804 Bond Strength (MPa) 7.08 8.26 6.16 4.76 5.26 11.79 11.73 12.49 The steel bars that were tested had bar diameters and embedment length similar to that of the AFRP bars. This phase in the testing consist of three groups of concrete from the first set of test (Group 1, 2 and Group 5). The bond strength for these bars stayed relatively close ranging from 11.78 MPa to 12.48 MPa. The trend line stayed primarily flat from Group 1 to Group 5. The data can be seen in the Figure 3b. The superplasticizer has shown to have a greater effect on the bond strength of the AFRP bars and SCC than the steel rebar. This is due to the physical interaction of the steel rebar and the SCC due to its physical characteristics. In Figure 3b, it shows that there is a small difference in the linear slope of the ACI 318.02 equation for bond strength of steel bars and the test result of the steel bar. The data received from the AFRP test were compared to the ACI equation for bond behavior of FRP bars and normal concrete. In this equation, the compression strength can be assumed to be a factor of the change in its water cement ratio. In Figure 3a, the ACI equation is plotted using the testing circumstances from this current testing. The data points for the ACI equation are compared to that of the test result from the pullout test. The first group of concrete containing zero dosage of superplasticizer, had a percentage error of 1.7% compared to the ACI equation. The data points are very close giving the fact that at Group 1 (contains no superplasticizer) it is normal concrete. From This point on, the difference in the data received and the ACI equation increases. The percent error for the second group is roughly 5.6 % from the ACI equations. From the second group to the third group, the difference in test result and equation increases drastically. The difference in the test results and the ACI equation continues to increase as the compression strength increases. This data shows the effects of the superplasticizer dosage add to the concrete. This data show that the optimal dosage is obtain at a dosage of 4 to 5oz. per 100 lbs. of cement. At this point, the concrete and bar reaches it maximum bond strength. © ASCE Structures Congress 2017 8 20 AFRP Steel ACI 318.02 16 SP=0 6 SP=6 SP=8 12 10 8 6 4 5 2 SP=7 SP=6 7 14 SP=5 SP=5 SP=0 8 Bond strength (MPa) Bond Strength (MPa) 9 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. b 18 SP=8 a Test results ACI 440.1R-06 SP=7 10 0 4 18 21 24 27 30 33 36 Compression Strength (MPa) 39 42 18 20 22 24 26 28 30 32 34 36 38 40 Compression strength (MPa) Figure 3 Evaluation of bond strength for AFRP and steel bars of present test, (a) Comparing bond strength of AFRP bars and ACI 440.1R-06, (b) Bond strength of AFRP, steel deformed bars, and ACI 318.02 equation (Anon., 2002) 6. Bond-Slip Model The dial gauges that were used had a maximum reading of 13.63 mm. For the bars that had a final slip greater than 13.63 mm, a modification factor was determined by comparing the data received from the dial gauges and the displacement giving from the UTM. With this information, the slip after 13.63 mm can accurately be accounted for. After this, the final slip is compared to the measurement of the actual slippage. The data received showed that reading from dial gauges were very close to the measurements of the actual slippage. The overall average shows that the data from the dial gauges were within 2% percent of the actual slippage measurement. In order to properly measure the bond slip model, dial gauges were used to measure the slippage of the AFRP bars. Once the data from the dial gauges and the UTM is received, the time interval was set equivalent in order to match the bond stress with the slippage at a specific time. Figure 4 shows that the bond slip relationship for the AFRP bars and for each group of SCC. The four groups differed in its water to cement ratio. The average bond-slip model for each group can be seen in Figure 4. This figure displays the ascending branch of each group. From this data gathered, the water cement ratio shows to have no real effects on the slope of the bond slip curve for the AFRP bars and the SCC. The slope at the earlier stages of the bond slip model for AFRP bars showed not to be as steep as that of steel. The data obtained shows that with decreasing the water to cement ratio, the slip at maximum bond stress increases. From Group 6 (0.44 w/c ratio) the slip at the maximum bond stress is at 4.61 mm. To Group 7 (0.4 w/c ratio), the slip increases by 44% to 6.64 mm. From this point to Group 8 (0.36 w/c ratio), there is an increase of 25% in slip. From Group 8 to Group 9 (0.32 w/c cement ratio) the slip increased by another 9.6 %. © ASCE Structures Congress 2017 9 Group 1 5.5 Group 2 Average of Group1 Average of Group 2 5 Bond Stress (MPa) Bond Stress (MPa) 4.5 4.0 3.5 3.0 2.5 2.0 4 3 2 1 1.5 1.0 0 0 1 2 3 4 5 -1 0 1 2 4 5 6 7 Group 4 Group 3 4.5 3 Slippage (mm) Slippage (mm) Average of Group 3 Average of Group 4 5 4.0 Bond Stress (MPa) 3.5 Bond stress (MPa) Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. 5.0 3.0 2.5 2.0 4 3 2 1.5 1 1.0 0 0.5 0 2 4 6 Slippage (mm) 8 10 0 2 4 6 8 10 Slippage (mm) Figure 4 Average Bond-Slip for each group of SCC 7. Conclusions This paper shows how the dosage of superplasticizer plays a factor into the bond behavior of the AFRP bar and the SCC. The effects of the amount of superplasticizer on the compression strength was investigated as well. The bond slip model of the AFRP bars with varying water cement ratio is displayed.  The optimal bond strength for the AFRP bar and SCC can be attained at a dosage of 4 and 5 ounces of superplasticizer per100 lbs. of cement. From this point, there is a decrease of 42.3% in bond strength from a dosage of 5 to 7 ounces per 100 lbs. cement (Group 2 to Group 4). This shows that the superplasticizer dosage has a great influence on the bond behavior.  The decrease in water cement ratio showed to have an opposite effect on the slip at the maximum bond stress. As the water cement ratios decreases from 0.44 to 0.32, the slip at maximum bond increases 98% in slip from a slippage of 4.61 mm to a slippage of 9.15 mm.  The compression test showed that increasing the dosage of superplasticizer has a positive effect on the compression strength. When increasing the superplasticizer dosage to 8 ounces per 100 lbs., the compression strength increased by 88% compared to normalweight concrete (0 oz. per 100 lb. cement) © ASCE Structures Congress 2017 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. References Anon., 1994. AS 3600, North Sydney, Australia: Australian Standard for Concrete Structures. Anon., 2002. ACI 318-02, Building Code Requirements for Structural Concrete, s.l.: s.n. Anon., 2003. ACI 408 R-03, Bond and Development of Straight Reinforcing Bars in Tension, s.l.: ACI Commitee. Anon., 2004. ACI 440, Guide Test Methods for Fiber-Reinforced Polymers (FRPs) for Reinforcing or Strengthening Concrete Structures, s.l.: ACI Committee. Anon., 2006. ACI 440.1R-06, Guide for the design and construction of concrete reinforced with FRP bars, Farmington Hills, Mich: American Concrete Institute (ACI). Brettmann, B. B., Darwin, D. & Donahey, R. C., 1986. Bond of Reinforcement to Superplasticized Concrete. Journal Proceedings, 83(1), pp. 98-107. Cosenza, E., Manfredi, G. & Realfonzo, R., 1997. Behavior and Modeling of Bond of FRP Rebars to Concrete. Journal of Composite for Construction, pp. 40-51. Esfahani, M. & Rangan, B., 1998. Local bond strength of reinforcing bars in normal strength and high strength concrete (HSC). ACI Structural Journal, 95(2), p. 96–106. Esfahani, M. R. & Rangan, V., 1998. Bond between normal strength and high-strength concrete (HSC) and reinforcing bars in splices in beams. ACI Structural Journal, Volume 95-3, pp. 272-280. Ghafoori, N., Najimi, M. & Aqel, M. A., (2014. Abrasion Resistance of Self-Consolidating Concrete. Journal Of Materials In Civil Engineering, pp. 296-303. Gibb, A., Glass, J., Goodier, C. & Rich, D., 2012. UK Contractors’ Views on Self-Compacting Concrete in Construction. ICE Publishing, Issue , pp. pp. 1-9. Golafshani, E. M., Rahai, A. & Sebt, M. H., 2014. Bond behavior of steel and GFRP bars in selfcompacting concrete. Construction and Building Materials, Volume 61, p. 230–240. Kassimi, F., El-Sayed, A. K. & Khayat, K. H., 2014. Performance of Fiber-Reinforced SelfConsolidating Concrete for Repair of Reinforced Concrete Beams. ACI Structural Journal, Volume 111-S108, pp. 1277-1286. Kocaoz, S., Samaranayake, V. & Nanni, A., 2015. Tensile Characterization of Glass FRP Bars. Composites, 24 Sept, 36(2), p. 127–134. Lee, Y. H., Kim, M. S., Kim, H. L. J. & Kim, D., 2013. Experimental study on bond strength of fiber reinforced polymer rebars in normal strength concrete. Journal of adhesion science and technology, 27(5-6), pp. 508-522. Lin, X. & Zhang, Y., 2013. Evaluation of bond stress-slip models for FRP reinforcing bars in concrete. Composite Structures, pp. 131-141. Melo, J., Rossetto, T. & Varum, H., 2015. Experimental study of bond–slip in RC structural elements the bond strength with plain bars. Materials and Structures, pp. 2367-2381. Okelo, R. & Yuan, R. L., 2005. Bond Strength of Fiber Reinforced Polymer Rebars in Normal Strength Concrete. Journal Of Composites For Construction, Volume 9.3, pp. 203-213. Orangun, C. O., Jirsa, J. O. & Breen, J. E., 1977. A Reevaluation of Test Data on Development Length and Splices. ACI Journal, pp. 114-122. Shen, D. et al., 2016. Experimental study of early-age bond behavior between high strength concrete and steel bars using a pull-out test. Construction and Building Materials, pp. 653663. Tastani, S. P., Pantazopoulou, S. J. & Karvounis, P., 2005. Local Bond - Slip Characteristics of G-FRP Bars. Conference Paper, pp. 1-17. © ASCE 10 Structures Congress 2017 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. Xing, G., Zhou, C., Wu, T. & Liu, B., 2015. Experimental Study on Bond Behavior between Plain Reinforcing Bars and Concrete. Advances in Materials Science and Engineering, pp. 19. Zia, P., Nunez, R. A. & Mata, L. A., 2005. Implementation of self-consolidating concrete for prestressed concrete girders, Raleigh: Federal Highway Administration, The United States Department of Transportation. © ASCE 11 Structures Congress 2017 12 Dolores River Bridge—Bedrock, CO: Remote Site Solution for Deep Scour Jonathan E. Emenheiser1 and Gregory S. Lingor2 1 Downloaded from ascelibrary.org by RMIT UNIVERSITY LIBRARY on 01/05/19. Copyright ASCE. For personal use only; all rights reserved. CH2M, Transportation Business Group, 9191 South Jamaica St., Englewood, CO 80112. E-mail: jon.emenheiser@ch2m.com 2 CH2M, Transportation Business Group, 9191 South Jamaica St., Englewood, CO 80112. E-mail: greg.lingor@ch2m.com Abstract The Dolores River Bridge in Bedrock, Colorado carries SH-90 over the Dolores River. The bridge is in a remote location and crosses a channel that has the potential for deep scour during the extreme flooding event. The structure was designed with a combined focus on cost, constructability, and hydraulic performance during both the design and extreme events. The superstructure consists of concrete bulb tee girders and precast deck panels and the substructure consists of steel H-piles with precast concrete abutment caps. All bridge components except the barrier curb were designed using precast concrete elements because the site location is far from ready-mix concrete plants. The precast elements were designed and detailed to connect using high strength threaded rods and tolerances were established to allow for field adjustment and avoid lengthy delays during construction. The 100-year flood event has the potential to lower the channel grade by nearly 17 feet. To mitigate this, the abutment walls and wing walls were designed using driven sheet piles with rip rap protection. For the 500-year extreme event, the abutment was designed to remain stable and allow the roadway embankment to be replaced, providing a much faster and more economical repair than a complete structural replacement. This paper presents the unique design challenges of this structure and the solutions that were developed and implemented to meet the challenges while providing a cost effective product. This paper will provide an understanding of bridge abutment design that combines deep foundations for structural stability during the extreme scour event and sheet pile wing walls for stability during the intermediate scour event. The paper will also provide an understanding of the design and detailing considerations for a bridge structure using entirely precast components. © ASCE
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